Tag Archives: shipping

Among the PFS instruments, “Cobra” modules position fibers to galaxies and stars on the Subaru Prime Focal plane. 42 Cobra modules, each of which consists of 57 fibers and its positioners, cover the entire PFS field of view without any inaccessible gaps as shown in Figure 1. PFS 観測装置の内、すばる望遠鏡の主焦点面上の銀河や恒星へファイバーを配置するモジュールは「コブラモジュール」と呼ばれています。57本のファイバーとアクチュエータで構成されるモジュールを42台、図１のように配置し視野を隙間なくカバーしています。 Two groups are collaborating to assemble “Cobra Modules”; Brazilian team responsible… Read more »

One of the PFS instrument “Metrology Camera” was finally shipped from Taiwan to Hawaii!! Metrology Camera is an instrument used to measure the fibers position while we configure fibers to target objects. Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan has the responsibility for Metrology Camera development, and they tested its performances before shipping in the last a… Read more »

In January 2018, the visible-blue camera cryostat of the first spectrograph module was shipped from Johns Hopkins University (JHU, the United States of America) to Laboratoire d’Astrophysique de Marseille (LAM, France). Visible-blue camera at Johns Hopkins University PFS are developing the four identical spectrograph modules, each of which has three channels with visible-blue, visible-red and near-infrared camera units, in order to… Read more »

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PFI accommodates about 2400 fibers and their positioners for scientific use, which are divided into 42 units of 57 fibers each. The fiber unit contains the fibers, fiber positioners, and electronic boards to control them. Therefore, each 42 rail has 57 holes, as the first picture.

Other than the rails with the science fibers, the bench accommodates a lot of different things such as 6 cameras for acquisitions and guiding of a target field, and fixed fibers as a reference during the fiber configuration of the astronomical object on the focal plane.

We will observe ~2400 objects using four identical spectrograph modules, each of which acquires ~600 spectra of astronomical sources and calibration sources. Each module covers wide wavelength range on visible and near-infrared band (380 — 1260 nm). To achieve this, the module has 3 camera units; visible-blue, visible-red and near-infrared. The light of each band is introduced by using two “dichiroic mirrors”, which split the light at a given wavelength.

To measure the fibers position on the focal plane, “Metrology Camera System” is attached on the Cassegrain focus of Subaru telescope. Looking up to the prime focus (see this image from HSC blog for clear image), this camera takes a image of back-illuminated fibers. Thanks to a large format of ~50 M pixels CMOS sensor, this camera can acquire all ~2400 fiber spots in a single exposure. The camera system is also designed to execute the process from exposure to measurement of fiber centroids within 5 seconds. Effective measurement of the fibers position enables us to shorten overhead for fiber configuration and execute large statistical survey observation.The Metrology Camera System will be delivered to Subaru in early 2018.

The Spectrograph Clean Room is a room whose size is 6.7 m wide, 8.6 m long ,and 3.6 m high. Four PFS spectrographs will be accommodated in the clean room. To stabilize the spectrograph performance, the temperature in the room will be controlled at 5 +- 1 degree Celsius. Besides, a crane with capability of 500 kg is installed for assembly and maintenance of the Spectrograph.